The present invention is directed to expansible chamber devices and, in particular, to expansible chamber devices in which working members comprise alternately approaching and receiving elements. The invention finds particular application in devices such as internal combustion engines, pumps, and fluid motors. The invention also relates to braking systems for controlling the motion of the working members in expansible chamber devices, including devices for controlling the intermittent rotation of the alternately approaching and receding elements used to define one or more expansible chambers. The invention further relates to rotating piston synchronizing systems for controlling the maximum extent of relative rotational motion between pairs of alternately approaching and receding elements of the expansible chamber device.
Expansible chamber devices generally operate by changing the volume defined between working members in order to compress a working fluid or gas. One form of known expansible chamber devices, for example, is that disclosed in U.S. Pat. No. 4,279,577. There, the device incorporates a pair of opposed rotating members comprising one or more radially extending veins or abutments to define, in part, an expansible chamber. Each of these members undergoes intermittent and alternating motion throughout the cyclic operation of the engine or pump. In devices of this type, the movement of the rotating members must be carefully controlled and synchronized. In the past, this control has been accomplished using control mechanisms which are complex in design and operation and which may be unreliable at higher operating speeds.
In U.S. Pat. No. 4,605,361, an oscillating vane rotary pump or motor uses a drive pin adapted to engage helical slots defined in coaxial rotor shafts and cam rollers to provide for oscillating the rotors and vanes with respect to each other as the rotors rotate with respect to the rotary pump or motor cylinder. In that system, a stationary cam is needed to permit the two pistons to rotate continuously as the output, or input in a pump, shaft rotates. Accordingly, that device is of little use in expansible chamber devices of the type including rotating pistons that intermittently rotate in the same direction during recurrent periods of rotation with each of the piston assemblies being stopped between the periods of rotation.
Sets of non-circular gears are used to control the relative positions of the rotating pistons in U.S. Pat. No. 5,381,766. The gears in that system, however, are difficult and expensive to manufacture and, further, do not provide a uniform perk output on the shaft.
It would, therefore, be desirable to provide a device for controlling the motion of the working members in an efficient and simple fashion which solves the problems recognized in the prior art. It would further be desirable to provide a device for controlling the relative angular position between the working members to be within a predetermined range for purposes of synchronizing them at start up when the expansible chamber device is used as an engine. The aforementioned problems are addressed by the present invention described in detail in this specification.